ziomon: Move dependency check for blktrace

When calling ziomon --version (or --help) the tool already checks
whether blktrace is present and prevents any output for those command
options when it isn't. This is unnecessary as no actual command is
issued during the parameter check and all other dependencies are checked
at a later point as well.

Move the dependency check to ensure a working --version and --help
option at any time.

Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

ziomon/ziomon

@@ -745,10 +745,11 @@ function check_size_requirements() {
 
 trap emergency_shutdown SIGHUP SIGTERM SIGINT SIGQUIT;
 
-check_blktrace;
 
 parse_params $@;
 
+check_blktrace;
+
 determine_host_adapters;
 
 check_cpuplugd;